Vitamin D: Diet, Supplement and/or Sunshine. You Pick
- 2 Minutes Read
Vitamin D, a fat-soluble vitamin, plays a significant role in how the body functions, from the major organs down to the cellular level. If preventing osteoporosis is not enough incentive for getting adequate vitamin D, consider that there is a growing body of evidence suggesting that the vitamin plays an important role in preventing and treating a variety of diseases. Do you know your serum vitamin D level?
Remember the last time you came home from a vacation at the beach, and your co-workers raved about your beautiful tan? Or the time you played golf, did yard work or went on a long bike ride and your family or friends commented on getting some sun? Well, in cases like these, beauty happens to be more than skin deep, and that sun exposure actually made you healthier than you thought or looked. It is not so much the healthy glow that stands out but the amount of vitamin D you absorbed by being in the sun
Vitamin D, a fat-soluble vitamin, plays a significant role in how the body functions, from the major organs down to the cellular level. It is essential for adequate calcium absorption and also helps maintain sufficient blood levels of calcium and phosphate. This is critical for a normal musculoskeletal system that is characterized by good bone growth, density and strength.
The human diet is usually a poor source of vitamin D because very few foods naturally contain it. The best sources are fatty fish (tuna, salmon, and herring) and fish liver oil. Vitamin D is also found in smaller amounts in liver, cheese, and egg yolks. Most of the vitamin D consumed in foods is found in those fortified with the vitamin. In the 1930s, the U.S. started a national milk fortification program to prevent rickets, a condition caused by vitamin D deficiency and a major health problem at that time. Today, other commonly fortified foods include yogurt, ready-to-eat cereal and orange juice.
The National Health and Nutrition Examination Survey, conducted 2005-2006, showed that the estimated vitamin D intake from food was inadequate. According to the results of the survey, average intake for males ranged from 204-288 IU/day. Female's average vitamin D intake ranged from 144-276 IU/day. The Federal Food and Drug Administration's Food and Nutrition Board established a Recommended Dietary Allowance (RDA) for vitamin D based on minimal sun exposure. This RDA is sufficient to maintain bone health (preventing osteoporosis) and normal calcium function. The RDA for ages 1 through 70 is 600 IU/day. See this page for a breakdown for all age groups, pregnancy and lactation.
It is thought that most people meet at least half of their vitamin D needs through sunlight exposure. Vitamin D is synthesized when the skin absorbs UV rays from sunlight. Vitamin D researchers suggest that approximately 5-15 minutes of sun exposure on about 6% of the body (face, arms, legs or back), 2-3 days per week, without sunscreen should lead to sufficient vitamin D synthesis. In other words, there is no need to get excessive sun exposure that can put you at risk of skin cancer. Individuals with limited sun exposure should consider taking a Vitamin D supplement. Most daily multivitamin-mineral supplements contain 400 IU vitamin D.
Serum concentration of 25(OH)D is the best indicator of vitamin D status. It reflects the amount of vitamin D stored in the body. There is on-going debate about levels needed to prevent deficiency, promote bone health and for optimal overall health. The Institutes of Medicine state that vitamin D deficiency risk occurs at <30 nmol/L and that all people are sufficient at ?50 nmol/L. In 2011, the Endocrine Society stated that the desirable serum 25(OH)D is >75 nmol/L for maximizing calcium, bone and muscle metabolism. Vitamin D toxicity occurs most likely from high-dose supplementation and can occur at levels of ?125 nmol/L. Symptoms of vitamin D toxicity include loss of appetite, weight loss and excessive urination.
If preventing osteoporosis is not enough incentive for getting adequate vitamin D, consider that there is a growing body of evidence suggesting that the vitamin plays an important role in preventing and treating type 1 diabetes, type 2 diabetes, high blood pressure and heart disease. There has been a lot of research looking at vitamin D's role in type 2 diabetes prevention. Vitamin D is essential for function of the pancreas, the organ that produces insulin. Insulin is the hormone that carries sugar out of the blood into the body tissues. The exact mechanism is not clearly understood, but it is being earnestly investigated.
Why not ask your doctor to check your serum vitamin D level? It is a reasonable, non-fasting blood test, and it if is low, you can take supplements to fill up your stores. Not only can this benefit your bone health, but you may be strengthening your prevention arsenal against type 1 and type 2 diabetes, high blood pressure and heart disease.Nutrients->Vitamin D